________________________________________________________________________________

International C175 Engine

The International Harvester C175 is a heavy-duty, inline 4-cylinder carbureted gas and liquid-petroleum gas (LPG) engine. Introduced in the mid-1950s as a successor to smaller-displacement blocks like the C169, it became a staple powerplant for mid-sized row-crop, utility, and industrial machinery. It is widely used across iconic International Harvester equipment, including the Farmall 350, IH 454 and 464 tractors, windrowers, and loader backhoes. The C175 is recognized in workshop settings as a rugged, low-maintenance engine engineered for continuous high-torque applications under heavy field loading. Depending on production year and application, the block configuration varied slightly between early wet-sleeve setups and later cast-in-bore (non-sleeved) versions.

The engine uses an overhead valve layout featuring a vertical I-head configuration. Valves are actuated via pushrods and rocker arms driven by a gear-driven camshaft nested inside the engine block. Standard Configurations: Features a bore diameter of 3.625 inches (92 mm) and a stroke length of 4.25 inches (108 mm), creating a total displacement of 175 cubic inches (2.9 Liters).

Fuel delivery functions through a traditional spark-ignition carbureted layout, accommodating either gasoline or LP gas. It utilizes an upstream single-barrel, side-draft or up-draft carburetor (commonly manufactured by IH or Zenith) featuring adjustable idle and main-jet circuits. Air intake cleaning is managed via an oil-bath system on early utility models, progressing to a heavy-duty dry element air cleaner in later industrial installations. Fuel delivery is mechanically regulated by an external mechanical flyweight governor to automatically alter throttle position and sustain set engine speeds under load fluctuations.

Lubrication is managed via a full-pressure internal flow system driven by a positive-displacement oil pump. Oil is forced through internal block galleries to the main bearings, connecting rod journals, camshaft lobes, and upward to the rocker arm assembly. Oil Filter: Equipped with a side-mounted oil filter assembly attached directly to the main block casting. The engine relies on a high-capacity, pressurized liquid-cooling setup. Coolant circulation is forced through the block and cylinder head passages via a front-mounted belt-driven centrifugal water pump, routing thermal load to a heavy-duty radiator structure regulated by a mechanical thermostat.

General Technical Data

Engine Specifications

Engine Model ............... International Harvester C175
Engine Type ............... 4-cycle inline 4-cylinder overhead valve liquid-cooled gasoline
Number of Cylinders ............... 4
Cylinder Arrangement ............... In-line vertical configuration
Engine Bore, in (mm) ............... 3.625 (92.1)
Engine Stroke, in (mm) ............... 4.25 (108.0)
Displacement, cu.in (L) ............... 175 (2.9)
Rated Engine Power (Farmall 350), hp (kW) ............... 42.4 (31.6)
Rated Engine Power (IH 350 Utility), hp (kW) ............... 45.2 (33.7)
Rated Engine Speed, rpm ............... 1750-2000
Peak Torque, lb-ft (Nm) ............... 132 (179) at 1200 rpm
Low Idle Speed, rpm ............... 425-475
High Idle Speed (No Load), rpm ............... 1925-2200
Compression Ratio ............... 7.0:1
Firing Order ............... 1-3-4-2
Cylinder Block Type ............... Cast iron monoblock design
Cylinder Head Type ............... Cast iron one-piece overhead valve structural block
Valve Train Layout ............... Overhead valve pushrod-actuated rocker arm system
Number of Valves per Cylinder ............... 2 (1 intake, 1 exhaust)
Main Bearing Shell Material ............... Babbitt or copper-lead alloy steel backed liners
Camshaft Drive Method ............... Direct-engagement helical spur gear train
Lubrication System ............... Full-pressure circulation circuit
Oil Pump Type ............... Gear-driven internal spur gear pump assembly
Oil Filter Type ............... Full-flow replaceable element cartridge
Cooling System ............... Forced circulation thermo-syphon assisted liquid cooling
Water Pump Type ............... Belt-driven centrifugal impeller layout
Air Cleaner Type ............... Oil bath multi-stage filtering module
Starting System ............... Electric starter
Ignition System ............... Battery-powered distributor or high-tension magneto module
Spark Plug Gap, in (mm) ............... 0.023-0.027 (0.58-0.69)
Distributor Point Gap, in (mm) ............... 0.020 (0.51)
Magneto Point Gap, in (mm) ............... 0.013 (0.33)
Electrical System, V ............... 6 or 12

Fuel System

Fuel Delivery Method ............... Gravity-fed or mechanical diaphragm fuel pump
Carburetor Manufacturer ............... International Harvester or Zenith
Carburetor Model Variant ............... IH 364587R91 or Zenith 61 Series unit layout
Carburetor Type ............... Updraft single-barrel venturi standard fuel mixer module
Carburetor Float Level Setting, in (mm) ............... 1.28 (32.5)
Choke Bore Diameter, in (mm) ............... 1.25 (31.8)
Main Jet Size Identification ............... Fixed orifice or adjustable needle valve
Idle Jet Size Designation ............... Fixed bleed arrangement calibrated internal passage layout
Fuel Tank Total Capacity, gal (L) ............... 17.0 (64.3)
Fuel Filter Core Element ............... Glass bowl sediment bowl module
Alternative Fuel Type Options ............... Liquid Petroleum Gas
LP Gas Regulator Manufacturer ............... Ensign Carburetor Company
LP Gas Vaporizer Type ............... Liquid-to-gas heat exchange jacket module
LP Gas Carburetor Model ............... Ensign Model R structural updraft induction unit arrangement
LP Gas Liquid Valve System ............... High-pressure manual shutoff needle assembly unit line split
LP Gas Vapor Valve System ............... Low-pressure regulation diaphragm safety interlock system module
Fuel Pump Static Pressure, psi (bar) ............... 2.5-4.5 (0.17-0.31)
Fuel Pump Actuation Method ............... Camshaft eccentric lobe mechanical lifter arm configuration
Air Intake Manifold Material ............... Cast iron dual-chamber induction unit
Exhaust Manifold Material ............... Cast iron thermal expansion
Governor Type ............... Centrifugal variable-speed mechanical flyweight
Governor-to-Carburetor Linkage ............... Solid steel rod layout

Dimensions and Weight

Overall Length, in (mm) ............... 34.2 (870)
Overall Width, in (mm) ............... 22.5 (570)
Overall Height, in (mm) ............... 38.7 (985)
Dry Weight, lbs (kg) ............... 615 (279)
Wet Weight, lbs (kg) ............... 665 (302)

Maintenance Data

Service Information

Compression Pressure at Cranking Speed, psi (bar) ............... 154 (10.6)
Compression Test Minimum Threshold Value, psi (bar) ............... 125 (8.62)
Compression Variation Between Cylinders, psi (bar) ............... 10 (0.69)
Oil System Pressure at Rated Speed, psi (bar) ............... 30-45 (2.07-3.10)
Oil System Pressure at Idle Speed, psi (bar) ............... 10 (0.69)
Coolant Operating Temperature Range, F (C) ............... 165-190 (73.9-87.8)
Thermostat Opening Start Temperature, F (C) ............... 160-165 (71.1-73.9)
Thermostat Full Open Temperature, F (C) ............... 185-190 (85.0-87.8)
Ignition Advance Timingl, deg BTDC ............... 22-25
Fan Belt Deflection Service Limit, in (mm) ............... 0.50 (12.7)
Intake Valve Clearance, in (mm) ............... 0.014 (0.36)
Exhaust Valve Clearance, in (mm) ............... 0.014 (0.36)

Engine Oil and Coolant

Engine Oil Type .................. SAE 30, SAE 10W, 20W, or 10W-30
API Service Classifications ......................... CC or CD
Engine Oil Capacity, qt (L) ............... 5.0 (4.7)
Cooling System Capacity, qt (L) ............... 19.0 (18.0)
Air Cleaner Oil Cup Capacity, pt (L) ............... 1.0 (0.47)

Service Intervals

Change oil and filter ............... Every 100 hours
Inspect air cleaner ............... Every 50 hours
Service air cleaner ............... Every 250 hours
Valve clearance adjustment ............... Every 500 hours
Fuel system inspection ............... Every 1000 hours
Change coolant ............... Every 1000 hours
Spark plug replacement ............... Every 500 hours
Check ignition system ............... Every 500 hours

Service Specifications

Cylinder Sleeve Bore Standard Diameter, in (mm) ............... 3.6250-3.6260 (92.075-92.100)
Cylinder Sleeve Bore Maximum Out-of-Round, in (mm) ............... 0.0015 (0.038)
Cylinder Sleeve Bore Maximum Taper, in (mm) ............... 0.0020 (0.051)
Cylinder Sleeve Top Flange Protrusion Deck, in (mm) ............... 0.002-0.005 (0.051-0.127)
Cylinder Head Flatness Warpage Limit, in (mm) ............... 0.0030 (0.076)
Cylinder Block Deck Flatness Surface Limit, in (mm) ............... 0.0040 (0.102)
Crankshaft Main Journal Diameter, in (mm) ............... 2.498-2.499 (63.45-63.47)
Crankshaft Main Bearing Oil Clearance, in (mm) ............... 0.0015-0.0033 (0.038-0.084)
Crankshaft End Play, in (mm) ............... 0.004-0.008 (0.102-0.203)
Connecting Rod Crankpin Journal Diameter, in (mm) ............... 2.124-2.125 (53.95-53.97)
Connecting Rod Bearing Oil Clearance, in (mm) ............... 0.0012-0.0030 (0.030-0.076)
Connecting Rod Big End Side Play Clearance, in (mm) ............... 0.005-0.010 (0.127-0.254)
Piston Pin Fit in Piston Bushing Bore, in (mm) ............... 0.0001-0.0003 (0.0025-0.0076)
Piston Pin Fit in Connecting Rod Bushing, in (mm) ............... 0.0003-0.0006 (0.0076-0.0152)
Piston-to-Cylinder Liner Skirt Clearance, in (mm) ............... 0.0035-0.0045 (0.089-0.114)
Top Ring Side Clearance, in (mm) ............... 0.0020-0.0035 (0.051-0.089)
Second Ring Side Clearance, in (mm) ............... 0.0015-0.0030 (0.038-0.076)
Oil Ring Side Clearance, in (mm) ............... 0.0015-0.0030 (0.038-0.076)
Top Ring End Gap, in (mm) ............... 0.010-0.020 (0.254-0.508)
Second Ring End Gap, in (mm) ............... 0.008-0.018 (0.203-0.457)
Oil Ring End Gap, in (mm) ............... 0.008-0.018 (0.203-0.457)
Intake Valve Head Diameter, in (mm) ............... 1.562 (39.7)
Exhaust Valve Head Diameter, in (mm) ............... 1.437 (36.5)
Valve Guide Inside Diameter, in (mm) ............... 0.3745-0.3755 (9.512-9.538)
Intake Valve Stem Outside Diameter, in (mm) ............... 0.3720-0.3730 (9.449-9.474)
Exhaust Valve Stem Outside Diameter, in (mm) ............... 0.3710-0.3720 (9.423-9.449)
Intake Valve Stem-to-Guide Clearance, in (mm) ............... 0.0015-0.0035 (0.038-0.089)
Exhaust Valve Stem-to-Guide Clearance, in (mm) ............... 0.0025-0.0045 (0.064-0.114)
Valve Spring Free Length, in (mm) ............... 2.125 (53.97)
Camshaft Journal Diameter, in (mm) ............... 1.873-1.874 (47.57-47.60)
Camshaft Journal Oil Clearance, in (mm) ............... 0.0015-0.0040 (0.038-0.102)
Camshaft End Play, in (mm) ............... 0.003-0.007 (0.076-0.178)
Cam Lobe Height (Intake), in (mm) ............... 0.285 (7.24)
Cam Lobe Height (Exhaust), in (mm) ............... 0.285 (7.24)

Tightening Torques

Cylinder Head Bolts (Step 1), lb-ft (Nm) ............... 45 (61)
Cylinder Head Bolts (Step 2), lb-ft (Nm) ............... 75 (102)
Cylinder Head Bolts (Final Step), lb-ft (Nm) ............... 85-90 (115-122)
Connecting Rod Cap Nuts, lb-ft (Nm) ............... 45-50 (61-68)
Main Bearing Cap Stud Nuts, lb-ft (Nm) ............... 80-85 (108-115)
Flywheel to Crankshaft Flange Bolts, lb-ft (Nm) ............... 55-60 (75-81)
Crankshaft Front Pulley Damper Nut, lb-ft (Nm) ............... 110-120 (149-163)
Camshaft Thrust Plate Screws, lb-ft (Nm) ............... 18-22 (24-30)
Camshaft Driven Timing Helical Gear Nut, lb-ft (Nm) ............... 65-75 (88-102)
Rocker Arm Shaft Support Bracket Bolts, lb-ft (Nm) ............... 25-30 (34-41)
Valve Cover Stamped Steel Hold-Down Nuts, lb-ft (Nm) ............... 7-10 (9-14)
Oil Pan Sump Perimeter Sheet Metal Bolts, lb-ft (Nm) ............... 12-15 (16-20)
Oil Pan Bottom Drain Sump Plug Hex Head, lb-ft (Nm) ............... 35-40 (47-54)
Intake Exhaust Manifold Clamp Stud Nuts, lb-ft (Nm) ............... 25-30 (34-41)
Water Pump Assembly to Front Block Bolts, lb-ft (Nm) ............... 15-18 (20-24)
Water Pump Pulley Fan Hub Hub Nut, lb-ft (Nm) ............... 25-35 (34-47)
Oil Pump Housing Cover Screws, lb-ft (Nm) ............... 15-18 (20-24)
Oil Pump Tube Flange Mount Bolts, lb-ft (Nm) ............... 12-15 (16-20)
Oil Pressure Relief Valve Cap Nut, lb-ft (Nm) ............... 40-45 (54-61)
Timing Gear Case Front Cover Bolts, lb-ft (Nm) ............... 15-18 (20-24)
Flywheel Housing Rear Adapter Block, lb-ft (Nm) ............... 45-50 (61-68)
Distributor Mounting Adapter Bracket Bolt, lb-ft (Nm) ............... 12-15 (16-20)
Spark Plug Thread, lb-ft (Nm) ............... 25-30 (34-41)
Governor Housing Assembly Mounting Bolts, lb-ft (Nm) ............... 18-22 (24-30)
Fuel Diaphragm Pump Flange Mount Nuts, lb-ft (Nm) ............... 14-17 (19-23)
Carburetor Flange Induction Manifold Mounting Nuts, lb-ft (Nm) ............... 18-22 (24-30)
Air Cleaner Mounting Brackets Structural Bolts, lb-ft (Nm) ............... 20-25 (27-34)
Starter Motor Flange Nose Housing Mounting Bolts, lb-ft (Nm) ............... 35-40 (47-54)
Generator Charging Unit Cradle Frame Bolts, lb-ft (Nm) ............... 25-30 (34-41)
Water Temperature Sender Dual Hex Plug, lb-ft (Nm) ............... 20-25 (27-34)

________________________________________________________________________________________

• International Engines Specs
  
• International C221 Specs
  
• International C263 Specs
  
• International C291 Specs
  
• International C301 Specs
  

______________________________________________________________________________________

________________________________________________________________________________________

_______________________________________________________________________________________

________________________________________________________________________________________

________________________________________________________________________________________

________________________________________________________________________________________

________________________________________________________________________________________

________________________________________________________________________________________

________________________________________________________________________________________